/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
 */
/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma weak __rintf = rintf

/* INDENT OFF */
/*
 * aintf(x)     return x chopped to integral value
 * anintf(x)    return sign(x)*(|x|+0.5) chopped to integral value
 * irintf(x)    return rint(x) in integer format
 * nintf(x)     return anint(x) in integer format
 * rintf(x)     return x rounded to integral according to the rounding direction
 *
 * NOTE: rintf(x), aintf(x) and anintf(x) return results with the same sign as
 * x's,  including 0.0.
 */

#include "libm.h"

static const float xf[] = {
/* ZEROF */     0.0f,
/* TWO_23F */   8.3886080000e6f,
/* MTWO_23F */  -8.3886080000e6f,
/* ONEF */      1.0f,
/* MONEF */     -1.0f,
/* HALFF */     0.5f,
/* MHALFF */    -0.5f,
/* HUGEF */     1.0e30f,
};

#define ZEROF           xf[0]
#define TWO_23F         xf[1]
#define MTWO_23F        xf[2]
#define ONEF            xf[3]
#define MONEF           xf[4]
#define HALFF           xf[5]
#define MHALFF          xf[6]
#define HUGEF           xf[7]
/* INDENT ON */

float
aintf(float x) {
        int hx, k;
        float y;

        hx = *(int *) &x;
        k = (hx & ~0x80000000) >> 23;
        if (k < 150) {
                y = (float) ((int) x);
                /*
                 * make sure y has the same sign of x when |x|<0.5
                 * (i.e., y=0.0)
                 */
                return (((k - 127) & hx) < 0 ? -y : y);
        } else
                /* signal invalid if x is a SNaN */
                return (x * ONEF);              /* +0 -> *1 for Cheetah */
}

float
anintf(float x) {
        volatile float dummy __unused;
        int hx, k, j, ix;

        hx = *(int *) &x;
        ix = hx & ~0x80000000;
        k = ix >> 23;
        if (((k - 127) ^ (k - 150)) < 0) {
                j = 1 << (149 - k);
                k = j + j - 1;
                if ((k & hx) != 0)
                        dummy = HUGEF + x;      /* raise inexact */
                *(int *) &x = (hx + j) & ~k;
                return (x);
        } else if (k <= 126) {
                dummy = HUGEF + x;
                *(int *) &x = (0x3f800000 & ((125 - k) >> 31)) |
                        (0x80000000 & hx);
                return (x);
        } else
                /* signal invalid if x is a SNaN */
                return (x * ONEF);              /* +0 -> *1 for Cheetah */
}

int
irintf(float x) {
        float v;
        int hx, k;

        hx = *(int *) &x;
        k = (hx & ~0x80000000) >> 23;
        v = xf[((k - 150) >> 31) & (1 - (hx >> 31))];
        return ((int) ((float) (x + v) - v));
}

int
nintf(float x) {
        int hx, ix, k, j, m;
        volatile float dummy __unused;

        hx = *(int *) &x;
        k = (hx & ~0x80000000) >> 23;
        if (((k - 126) ^ (k - 150)) < 0) {
                ix = (hx & 0x00ffffff) | 0x800000;
                m = 149 - k;
                j = 1 << m;
                if ((ix & (j + j - 1)) != 0)
                        dummy = HUGEF + x;
                hx = hx >> 31;
                return ((((ix + j) >> (m + 1)) ^ hx) - hx);
        } else
                return ((int) x);
}

float
rintf(float x) {
        float w, v;
        int hx, k;

        hx = *(int *) &x;
        k = (hx & ~0x80000000) >> 23;
#if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
        if (k >= 150)
                return (x * ONEF);
        v = xf[1 - (hx >> 31)];
#else
        v = xf[((k - 150) >> 31) & (1 - (hx >> 31))];
#endif
        w = (float) (x + v);
        if (k < 127 && w == v)
                return (ZEROF * x);
        else
                return (w - v);
}